Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Takeshi Sekiguchi Last modified date:2022.01.04

Assistant Professor / Molecular Biology / Department of Molecular Biology / Faculty of Medical Sciences


Presentations
1. Phylogeographic Study of the Eurasian otter Lutra lutra in the littoal region of East Asia.
2. Hiroshi SASAKI* (Chikushi Jogakuen Univ.), Takeshi Sekiguchi (Kyushu Univ.) , Masako Izawa (Ryukyu Univ.) , Nozomi NAKANISHI (Ryukyu Univ.), Daisuke WAKU (Tokyo Univ. of Agriculture), Akihiro YAMANE (Seinan Univ.), 日本におけるユーラシアカワウソの発見, 14th International otter congress , 2019.04, In Japan, the last otter was observed at Kochi Pref. in 1979 before our finding and Government declared their extinction in 2012. In Feb., 2017, one otter was recorded at Tsushima Island, located between Korean and Kyushu Island in Japan, by a photo-trap which was set for survey of leopard cat. Surveys in July, from August to September, 2018 and in Dec., 2019 conducted to study their distribution and number. Photo traps were set from Dec., 2018 to Mar., 2019 for otters and feces has incidentally been collected by support of naturalists. Otters were recorded by photo-traps four times. DNAs were extracted from collected feces and 12 feces of otters were confirmed by Mitochondrial DNA. DDX3X, DDX3Y and SRY genes on sex chromosome were used for sex identification and micro-satellites for individual identifications. Existence of two males and one females at least were confirmed. Locations of feces were scattered through the island, and they might not be sedentary. Otters were recorded only in about 1735 and 1809 at this island. Haplotype of mitochondrial DNA coincide with it in southern parts of Korea. These otters are assumed to come to Tsushima Island by Tsushima current.

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3. RagA, a mTORC1 regulator, interacts with the WDR35 protein..
4. Search for a novel factor involving in metabolism of oxidized mRNAs .
5. A role of S.cerevisae Gtr1p on toxic substance exclusion.
6. 関口 猛, Riyoko Itoh, Hiroshi Hayakawa, Mutsuo Sekiguchi, Elimination of oxidized nucleic acid, 第86回日本生化学会大会, 2013.09, During the de novo synthesis of guanine nucleotides, GMP is formed first, which is converted to GDP by guanylate kinase (GMK), an essential protein for E.coli. This enzyme hardly acts on an oxidized form of GMP (8-oxo-GMP), formed by the oxidation of GMP or by the cleavage of 8-oxo-GDP and 8-oxo-GTP by MutT protein. Although the formation of 8-oxo-GDP from 8-oxo-GMP is thus prevented, 8-oxo-GDP itself may be produced by the oxidation of GDP by ROS. The 8-oxo-GDP thus formed can be converted to 8-oxo-GTP, since nucleoside diphosphate kinase and adenylate kinase, both of which catalyze conversion of GDP to GTP, do not discriminate 8-oxo-GDP from normal GDP. The 8-oxo-GTP produced in this way and also by the oxidation of GTP can be used for RNA synthesis. This misincorporation is prevented by MutT protein, which has a potential to cleave 8-oxo-GTP as well as 8-oxo-GDP to 8-oxo-GMP. When 14C-labeled 8-oxo-GTP was applied to CaCl2-permeabilized cells of mutT- mutant strain, it could be incorporated into RNA at 4% of the rate for GTP. Escherichia coli cells appear to possess mechanisms to prevent misincorporation of 8-oxo-Gua into RNA..
7. Analysis of fate of guanine nucleotide exogenously introduced into HeLa cells..
8. Interaction between Gtr1-Gtr2 and components of Tor complex1.
9. Analysis of distinction between Gtr1 and Gtr2 of heterodimeric Gtr1-Gtr2 complex of Tor signal transduction pathway..
10. Gtr1 or Gtr2 of hetero dimeric G proteins interacts to its interacting protein, Ego1 or Ego3..
11. Analysis of Gtr1-Gtr2 complex on TOR signal transduction pathway..
12. Individual Identification of Mustela .
13. Distribution and food habits of Japanese weasels Mustela itatsi at Gokayama in Sebri Mountains, Fukuoka, Japan.
14. Leucine zipper motifs are essential for Gtr1p-Gtr2p complex formation..
15. Characterization of Gtr1/2 small G proteins..
16. Protein phosphorylation of RCC1, a RanGEF.
17. Mutations in the Ran system genes affect silencing ability at telomere in budding yeast.
18. Yeast UBL-UBA protein Dsk2 interacting factor DIF1 particitates in hyperosmotic stress sensitivity.
19. K28-linked polyubiquitination of the Dsk2 UBL domain mediate its own degradation in yeast.
20. T44N mutant form of GTR2, a stress response G protein, complements gtr2 disruption..
21. A study on the possible function of S23N GTR2 (GDP form).
22. International Symposium on Ran and cell cycle.
23. Phosphorylation of DEAD-box RNA helicase DDX3 by mitotic cyclin B-dependent kinase (Cdc2).
24. A nucleolus protein Nop132, which associates with the GTP binding protein, RRAG A, also associates with nucleolar proteins, DDX18, DDX47, and Rpl3 ..